add optional request field to record time at which client made request

pkg/analysis_server/test/protocol_test.dart

Index: pkg/analysis_server/test/protocol_test.dart
diff --git a/pkg/analysis_server/test/protocol_test.dart b/pkg/analysis_server/test/protocol_test.dart
index e4bcb2168a4775fbe24005a6da0da203132ec7d6..544e9c5513f8e5d5d35fcd7c1254f678b59a53ca 100644
--- a/pkg/analysis_server/test/protocol_test.dart
+++ b/pkg/analysis_server/test/protocol_test.dart
@@ -149,6 +149,7 @@ class RequestTest {
     Request request = new Request.fromString(json);
     expect(request.id, equals('one'));
     expect(request.method, equals('aMethod'));
+    expect(request.clientRequestTime, isNull);
   }
 
   void test_fromJson_invalidId() {
@@ -171,6 +172,28 @@ class RequestTest {
     expect(request, isNull);
   }
 
+  void test_fromJson_withBadClientTime() {
+    Request original = new Request('one', 'aMethod', null, 347);
+    Map<String, Object> map = original.toJson();
+    // Insert bad value - should be int but client sent string instead
+    map[Request.CLIENT_REQUEST_TIME] = '347';
+    String json = JSON.encode(map);
+    Request request = new Request.fromString(json);
+    expect(request.id, equals('one'));
+    expect(request.method, equals('aMethod'));
+    // Verify that bad value is ignored

[Brian Wilkerson, 2015/01/23 14:57:20]

We should not ignore an invalid value. The field is optional, so clients can
omit it if they don't want to report it, but if they report it and it's wrong we
should let them know.

[danrubel, 2015/01/23 16:00:43]

Good point. Done.

+    expect(request.clientRequestTime, isNull);
+  }
+
+  void test_fromJson_withClientTime() {
+    Request original = new Request('one', 'aMethod', null, 347);
+    String json = JSON.encode(original.toJson());
+    Request request = new Request.fromString(json);
+    expect(request.id, equals('one'));
+    expect(request.method, equals('aMethod'));
+    expect(request.clientRequestTime, 347);
+  }
+
   void test_fromJson_withParams() {
     Request original = new Request('one', 'aMethod', {
       'foo': 'bar'
@@ -223,8 +246,7 @@ class ResponseTest {
   }
 
   void test_create_unanalyzedPriorityFiles() {
-    Response response =
-        new Response.unanalyzedPriorityFiles('0', 'file list');
+    Response response = new Response.unanalyzedPriorityFiles('0', 'file list');
     expect(response.id, equals('0'));
     expect(response.error, isNotNull);
     expect(response.toJson(), equals({